Factoring matrix expressions, even trivial ones?

Hi Henry:

I thought I was being simple-minded, but I also thought you might have 
your blinders on this morning, so I took the plunge and sent the 
message. Now I know something I didn't know before.

Thanks for replying,

Paul Bowyer

On 05/03/2013 09:44 AM, Henry Baker wrote:
> Hi Paul:
>
> The problem is that with a very large/complicated matrix, I might not be able to easily notice what factors exist in every entry.
>
> Stavros basically answered my question in the negative: there isn't a built-in way to do this, but by 'flattening' the matrix
> into a list, he can compute the GCD of this list, and then divide it out.
>
> At 09:19 AM 5/3/2013, Paul Bowyer wrote:
>> On 05/03/2013 06:30 AM, Henry Baker wrote:
>>> Is there any way for Maxima to factor 'a' back out of a*M, as below?
>>>
>>> Maxima 5.28.0-2 http://maxima.sourceforge.net
>>> using Lisp GNU Common Lisp (GCL) GCL 2.6.8 (a.k.a. GCL)
>>> Distributed under the GNU Public License. See the file COPYING.
>>> Dedicated to the memory of William Schelter.
>>> The function bug_report() provides bug reporting information.
>>> (%i1) M:transpose([x,y]);
>>>                                       [ x ]
>>> (%o1)                                [   ]
>>>                                       [ y ]
>>> (%i2) a*M;
>>>                                      [ a x ]
>>> (%o2)                               [     ]
>>>                                      [ a y ]
>>> (%i3) %,factor;
>>>                                      [ a x ]
>>> (%o3)                               [     ]
>>>                                      [ a y ]
>>> (%i4) ????
>> Does this do want you want? (My ignorance might be showing)
>>
>> M:transpose([x,y]);
>> M2:a*M;
>> M:M2/a;
>>
>> Paul Bowyer
>